The DM I play with for encounters passes out these power cards that are either a free action or a non-action (can't remember) encounter power that lets you add to a skill check roll, add a damage die, add a to hit roll, or gain an extra minor action. I can't for the life of me remember what it is called, but he did say its out of either DMG or DMG2, though it may be simply something he designed himself.
Hmmm, so I was wrong and it was completely DM fiat w/ him putting in a lot of time to create a power card for his house-rule. Sorry to have wasted your time.
The program used to create the power cards: http://magicseteditor.sourceforge.net/
the power card templates: http://www.dungeoncrawl.us/power_cards/
I'll post again when I have an example of the exact power/ability I was talking about.